Answer:
The Answer is Albrecht Dürer.
Step-by-step explanation:
He was one of the most prominent artists of his time, best known for his landscapes and studies related to human proportion - at this point, he and Da Vinci were similar.
Well, explaining the statement of your question. Albrecht Dürer was an artist with a theoretical approach, which means that he just not observe what was around him, but study and research to obtain a better viewpoint of the work. His critiques expressed in the book cited by the question - A Course in the Art of Measurement with Compass and Ruler - was toward the artists of his homeland that were more preoccupied to obtain a good look for the painting, but they forgot to understand the world they look at so deeply. Comparing with the Italian artists, Dürer states that the use of mathematics, especially the euclidian geometry, was a precious tool that let the artist create a masterpiece. A good example is the use of perspective, developed by the Renaissance artist, highlighting Filippo Brunelleschi, one of the first artists to use the perspective.